As long as The Aetherspark is attached to a creature, The Aetherspark can't be attacked and has "Whenever equipped creature deals combat damage during your turn, put that many loyalty counters on The Aetherspark."
[+1]: Attach The Aetherspark to up to one target creature you control. Put a +1/+1 counter on that creature.
Near Mint - $50.50
Lightly Played - $45.40
Played - $35.30
Heavily Played - $30.30
Damaged - $25.20
Near Mint Non-English - $50.50
Lightly Played Non-English - $45.40
Played Non-English - $35.30
Heavily Played Non-English - $30.30
Damaged Non-English - $25.20
Foil Prices
Near Mint Foil - $78.10
Lightly Played Foil - $70.30
Played Foil - $54.70
Heavily Played Foil - $46.90
Damaged Foil - $39.10
Near Mint Foil Non-English - $78.10
Lightly Played Foil Non-English - $70.30
Played Foil Non-English - $54.70
Heavily Played Foil Non-English - $46.90
Damaged Foil Non-English - $39.10